I am gonna share a discussion with you all that,s bin up here during the winther. Should you let your engine warm up a bit before driving?perhaps the time it takes to scrape off ice from the Windows. Or remove ice first and then just start and go?

The side on the start and drive made the following points.

1. The catalyst converter don,t work till the engine is warm and therefore will pollute more.

2. The engine doesn't warm up at idle but has to work before getting warm.

3. You will delute your engine oil with petrol due to blowby(or undercompression as it,s called here). And incomplete burning(don,t know how else to translate it)

4. Many modern engines has a pretty low oilpressure at idle, to reduce internal mechanical drag. And therefore. The wear is bigger.

The side that,s for letting the engine idle while scraping of ice.

1 the engine will mostly need between 15-20 sec before being fully lubricated(Probertly mostly with older thicker types of oil and engines.

2. The idle at cold start is often pretty high. An example is my Mazda that idles at 2000 rpm at cold start. Therefore it incomplete burning ain,t that big a problem.

3. In favor of safety it is best if the car is free of any moist of the Windows before ddriving. It is hard when you do the start and go way.

So. What do all the experts here say? This winther has bin really mild. But a normal whinther we will have night temps down to -15--20 celcius..

I apologize if my spelling is bad. I am sitting up at night, becouse I have the pneumonia. On both lungs. So now at is tea and rum time:-)

I do not see a need for a long warm up, but warming up the car while one scrapes ice off the windows seems reasonable. But if its cold and no ice, then as soon as I see oil pressure in my gauge I will drive off.

Now if its below 5F my Jeep makes some odd engine noises, so I wait until the engine sounds normal (which might be a minute or two) then drive off.

And then there are the days I use the remote starter because I do not want to be cold.

My rule is that I'll wait five to 10 seconds in the summer and then drive. That works well until the freezing point and then I'll add another 5 seconds, when it gets near 0 Fahrenheit I'll wait maybe 30 seconds. Waiting longer really serves no purpose. There is nothing wrong with waiting longer for whatever reason, you may not gain much, but there is no harm.

The thing to keep in mind is that it's not only the engine that needs to have oil circulated throughout before driving off, regardless of temperature, but the transmission, power steering, drive axle, etc. The colder it is the longer it takes for fluids to circulate. So, once you're rolling, go easy for a few miles and then let it rip.

As for making allowances for "incomplete burning", or letting the converter warm up or pollution, don't worry about that. If you're really worried about pollution ride a bicycle.

I would say much depends on how hard you will work the engine once you get going.I have the luxury that I have about 1 minutes driving before I need to even get up to 50kph.So, (unless I need to scrape) I start and Go.

I agree its better to start up and drive off leisurely. But I have wondered about situations in cold weather where you have to accelerate into traffic right off the bat. Are you better to let it run 5 minutes or just start up and go even if you are hitting say 4k rpm?

Just because the engine has oil pressure doesnt mean its lubricated. I let it idle until the rpm starts to drop down, then I put it in drive and take it easy until its warmed up.

That's pretty much exactly what it means...

I like the thought mentioned above, that my vehicle serves me, not the other way around. When I'm by myself, the temperatures aren't ridiculously low, and/or the humidity doesn't mean instant-visibility-killing fog I clear the windows, if applicable, start, and drive off. Otherwise, I'll warm'er up for a minutes while clearing snow and setting the defroster on high, or remote-start and let'er warm up if that's what I want that time.

When i was a kid back in the 80's my neighbor would wake me up in the morning 'warming up' his car. His 'warming up' consisted of starting the car and holding his foot on the accelerator revving it to ungodly rpm's for about two minutes, then drop it in drive and go. Even as a kid i didn't think this was the best method. For me, start it up, i can scrape the windows in about a minute, then drive it easy.

Modern cars with properly working and heated O2 sensors should go closed loop pretty fast. How well/fast they get out of the algorithm holding idle a bit faster may be a different story. However if you can go closed loop, you don't have a ton to worry about.

So IMO the best thing from an engine longevity point of view is to use a block heater if equipped, then to start the car, let it stabilize for a few seconds to perhaps a minute at most, then go. Driving should always be gentle, but especially for the first 20 miles/minutes. However, that's the case in ANY weather. When combustion processes are over 1000 degrees, and cooling systems are designed to disperse all heat in >100 degree conditions, the difference in operation from a cold design day to a hot one is kind of small.